Starr is working on a followup to his 2015 album Postcards from Paradise. He said in an interview with Rolling Stone in July that he's "well into" the project, but told the magazine it might be "March" before it's finished.

"The ways I've been working over the last several years is that I do sort of a rhythm-pattern synth track. And then I play drums and go, 'Oh, there's a verse. Oh, that sounds like a chorus.' And then I call writers in and say, 'Let's write something to that!'" the star shared.

"I love to play, and I'm still playing. I'm playing with great musicians, singers, writers. So, I'm blessed I'm still doing it, really," he added.

Starr and McCartney came to fame with the Beatles in the 1960s, and last collaborated on the drummer's 2010 album Y Not. The pair were spotted at dinner with Walsh, Dave Grohl and Tom Hanks last week in Santa Monica, Calif.